<?php
//$number1 = 20;
//$number2 = 30;
//if ($number1 > $number2) {
//    echo 'number1 大';
//} else {
//    echo 'number2 大';
//}
//
//var_dump($number1 != $number2);

$number1 = 0;
$number2 = null;
$number3 = '';

//if ($number3 === $number2) { // 恒等
//    echo 'AAAAAAAAAAAAAAA';
//} else {
//    echo 'BBBBBBBBBBBBBBB';
//}

//if (empty($number3)) {
//    echo 'AAAAAAAAAAAAAAA';
//} else {
//    echo 'BBBBBBBBBBBBBBB';
//}

//if (isset($number4)) {
//    echo 'AAAAAAAAAAAAAAA';
//} else {
//    echo 'BBBBBBBBBBBBBBB';
//}
//$score =20;
//if ($score > 100 || $score < 0) {
//    echo '成绩无效';
//} else {
//    if ($score >= 90) {
//        echo '优秀';
//    } elseif ($score >= 80) {
//        echo '良好';
//    } elseif ($score >= 70) {
//        echo  '中等';
//    } else {
//        echo '差';
//    }
//}


$status = 3;
//if ($status == 1) {
//    $statusTitle = '待付款';
//} elseif($status == 2) {
//    $statusTitle = '待收货';
//} elseif ($status == 3) {
//    $statusTitle = '已完成';
//} else {
//    $statusTitle = '已取消';
//}
//echo $statusTitle;
switch ($status) {
    case 1: $statusTitle = '待付款'; break;
    case 2: $statusTitle = '待收货'; break;
    case 3: $statusTitle = '已完成'; break;
    default: $statusTitle = '已取消';
}
echo $statusTitle;




